The ameliorative effects of high dose pentobarbital loading on ischemic brain and heart will be respectively evaluated in monkeys and dogs. Global brain ischemia will be acheived in monkeys with a neck tourniquet following a wide cervical laminectomy performed at an earlier date. Upon establishment of a reproducible neurologic deficit in controls, barbiturates will be administered and their possible ameliorative effect on brain damage measured. In dogs myocardial infarction will be produced by occlusion of the left anterior descending artery. The effects of barbiturate therapy on myocardial necrosis will be quantitated with morphologic and biochemical (CPK) assays.